virtualbox.exec how works?

[cekkr]

virtualbox.exec it's a very cool feature. But I have to understand some things:

• it writes commands emulating keys pressing? (Is possible with Virtual Box to write and read programmatically VGA text?)
• it works just with Guest Additions?

Thank you

[colonelpopcorn]

I'm not sure how it works under the hood, but this library uses the VBoxManage controlvm <vm> keyboardputscancode <hex> [<hex>...] command. Here's the relevant documentation page. It is not possible to read the contents of the screen, but other text based tools like SSH should do that for you. I don't think it needs guest additions to work. Does that answer your question?

[cekkr]

Ever on the doc it provides you several functions for guest control: https://docs.oracle.com/en/virtualization/virtualbox/6.0/user/vboxmanage-guestcontrol.html

It's very interesting but it doesn't specify how it works (and when it works). Anyway, very useful features. Thank you!

[colonelpopcorn]

Right, we're just using the command line options that VBoxManage exposes. If you'd like to dig deeper, VirtualBox source code can be found here, and the function that actually sends the codes to the VM can be found here